The recurrence rate and significance of low oestriol excretion in successive pregnancies.

A total of 440 women who had low oestriol excretion in a previous pregnancy was investigated by urinary oestriol assays in one or more subsequent pregnancies. The incidence of low oestriol excretion in the subsequent pregnancy was 29.1 per cent, or more than double that in the total obstetric population (13.4 per cent; p less than 0.001). Patients with persistently low oestriol excretion had a 40.8 per cent recurrence rate in subsequent pregnancies. When oestriol excretion was low in successive pregnancies it retained a significant association with increased incidences of stillbirths, neonatal deaths and fetal growth retardation. It was concluded that low oestriol excretion in a previous pregnancy is a definite indication to test fetoplacental function in subsequent pregnancies even when the clinical findings are normal.